PANCREAS - by vikas lodhi

Pancreas

The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates. In humans it is located in the abdominal cavity behind the stomach. It is an endocrine gland producing several important hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide which circulate in the blood. The pancreas is also a digestive organ, secreting pancreatic juice containing digestive enzymes that assist digestion and absorption of nutrients in the small intestine. These enzymes help to further break down the carbohydrates, proteins, and lipids in the chyme.

Structure

The pancreas is an endocrine organ that lies in the abdomen, specifically the upper, left abdomen. It is found behind the stomach, with the head of the pancreas surrounded by the duodenum. The pancreas is typically 5.75-9.5 cm long.

Anatomically, the pancreas is divided into a head, which rests within the concavity of the duodenum, a body lying behind the base of the stomach, and a tail, which ends abutting the spleen. The neck of the pancreas lies between the body and head, and is in front of the superior mesenteric artery and vein. The head of the pancreas surrounds these two vessels, and a small uncinate process emerges from the lower part of the head, lying behind the superior mesenteric artery.

The pancreas is a secretory structure with a internal hormonal role (endocrine) and an external digestive role (exocrine). It has two main ducts, the main pancreatic duct, and the accessory pancreatic duct. These drain enzymes through the ampulla of Vater into the duodenum.

Margin

 

The superior margin of pancreas is blunt and flat to the right; narrow and sharp to the left, near the tail.

It commences on the right in the omental tuberosity, and is in relation with the celiac artery, from which the hepatic artery courses to the right just above the gland, while the lienal artery runs toward the left in a groove along this border.

The inferior margin of pancreas separates the posterior from the inferior surface;the superior mesenteric vessels emerge under its right extremity.

The anterior margin of pancreas separates the anterior from the inferior surface of the pancreas, and along this border the two layers of the transverse mesocolon diverge from one another; one passing upward over the anterior surface, the other backward over the inferior surface.

Surfaces

The inferior surface of pancreas is narrow on the right but broader on the left, and is covered by peritoneum; it lies upon the duodenojejunal flexure and on some coils of the jejunum; its left extremity rests on the left colic flexure.

The anterior surface of pancreas is the surface of the pancreas that faces the front of the abdomen. The greater part of the right half of this surface is in contact with the transverse colon, with only areolar tissue intervening.

From its upper part the neck springs, its right limit being marked by a groove for the gastroduodenal artery.

The lower part of the right half, below the transverse colon, is covered by peritoneum continuous with the inferior layer of the transverse mesocolon, and is in contact with the coils of the small intestine.

The superior mesenteric artery passes down in front of the left half across the uncinate process; the superior mesenteric vein runs upward on the right side of the artery and, behind the neck, joins with the lienal vein to form the portal vein.

Function

The pancreas is a dual-function gland, having features of both endocrine and exocrine glands.

Clinical relevance

A puncture of the pancreas, which may lead to the secretion of digestive enzymes such as lipase and amylase into the abdominal cavity as well as subsequent pancreatic self-digestion and digestion and damage to organs within the abdomen, generally requires prompt and experienced medical intervention.

                                                

Vikas Lodhi